1. Field of the Invention
The present invention relates to a light source discretely oscillating a desired wavelength and, in particular, to a wavelength-variable light source loaded in an apparatus for measuring a loss distribution of a branch optical line whose one end is divided into a plurality of light-branching lines, and an OTDR apparatus.
2. Related Background Art
A conventional OTDR apparatus is disclosed in Japanese Patent Application Laid-Open No. 2-141641, which indicates that a wavelength-variable light source is efficient for inspecting a defect or a physical quantity such as temperature within a system to be measured having a branch device.